Radio receiving set



N0V- 13, 1934- E. F. ANDREWS RADIO RECEIVING SET Filed July 31. 1950 5Sheets-Sheelt l NV. 13, 1934. E F, ANDREWS RADIO REcEIvwGsET Filed July3l, 1930 (n/wier:

? 5 Sheets-Sheet 2 MrK/fmwdf M w M Nov. 13, 1934. v E F-.IANDREws1,980,842

Ramo RCEIVING SET Filed July 19511v 5 sheets-sheet 5 4 .y (jig. 5.

@Merini (ffwaw/wrem Nov. 13, 1934. E, F, ANDREWS 1,980,842

' mmm nEcEIvING sET yFiled July 31. 24 5 sheets-sheet 4 zal PatentedNov. 13, 1934 UNITED STATES raden lPATEN r [corsica 11 Claims.

This invention relates, in general, to systems and sets for receivingWireless signals and it per the amplifier stages are arranged one abovethe otherI and so connected as to minimize the effects of feedback.

A further important object of the invention is the provision of a novelradio receiving set or system in which the major dimension of thecabinet is determined by the vertical arrangement of the receivingapparatus therein and by the convenient height of the control devicesarranged on top of the cabinet.

Still another important object of the invention is the provision of anovel radio receiving set provided with a chassis or mounting frame ofsuch construction as to permit the efcient utilization of mounting spacewithin the cabinet or housing for the receiving set.

Another object of the invention is theprovision of a novel radioreceiving set or system having an open-top cabinet and a control panelproviding a closure for the open-top cabinet.

Another' object of this invention is the provision of a novel chassis orframe for radio receiving sets, positionable in a cabinet and removableltherefrom, through the top of the cabinet.

Still another object of the invention is the provision of a novel radiochassisv or frame which is so formed or shaped as to promote mechanicalstability and as to provide a shield for the ca- 40 pacity affectedapparatus mounted thereon.

A further object of the invention is the provision of a substantiallyL-shaped radio chassis or frame receivable` in an open-top cabinet andhaving radio receiving apparatus mounted on all sides of the chassiswhereby the vertical and horizontal` arms of the L-shaped chassis serveas shields between the apparatus mounted on opposite sides thereof.

Another object of the invention is the provision of a substantiallyL-shaped radio chassis or frame having centering means adapted toproject through the bottom of a cabinet for securing the chassistherein.

Another object of the invention is the provision cf a novel radioreceiving set having an instruA (Cl. Z50-14) ment mounting frame orchassis suspendedfrom the top of the cabinet.

Another object of` this invention is the provision of a novel mountingfor a radio chassis in an open-top cabinet.

A further object of the invention is the pro# vision of a tuningindicator or indicating means secured at the top of a novel radiochassis and adapted to actuate the tuning means of the set carried bythe chassis. I

Other objects and advantages of the invention will be apparent from thedrawings and as the following description proceeds, these objectsincluding, generally, the provision of a novel radio receiving set whichis compact ina'ssembly, yet free from the disturbances produced bycoupling between adjacently positioned apparatus and between adjacentlyarranged Wires; which may be readily dismantled for purposes ofinspection`1"e pair andreplacement of parts; which is so con'- structedas to permit its convenient `control by an operator in any conventionalposture; and which is sightly in appearance and readily adaptable forremote control or for moving from place to place to render it accessiblevat various desired places in the building where it is operated or used.

1n the drawings:

Figure 1 is a perspective view of a radio receivingset embodying thefeatures of the-invention;

Figure 2 is a vertical section through the cabinet showing a side viewof the chassis or frame in the cabinet; f

Figure 3 is aside elevation of the chassis shown in Figure2, showingparts of the chassis in section and parts cut away;

Figure 4 is an elevation of another side of the chassis;

Figure 5 is a section taken substantially on the line 5-5 of Figure 4;

Figure 6 is a horizontal section taken substantially on the line 6 6 ofFigure 2,' the chassis b eing removed from the cabinet; 1

Figure 7 is a section takensubstantially on the line-7 3? of Figure2;and

Figure 8 is a circuit diagram of a receiving set or system,schematically showing .one arrangement of a radio set for the cabinet ofFigure 1.

In order to accomplish the foregoingobjects, the instant invention, asillustrated, contemplates the arrangement of coupling coils andamplifier tubes one above the other in an upright cabinet and soconnecting the coupling coilsand ampliiier tubes that the tube leadwires or connecting Wires' are of such length that the couplingtherebetweeny iS .Iltgligble.v Thismay be accomplished by con-y nectingthe second coil from the top to the antenna, that is, by utilizing thiscoil as the first stage primary input coil and connecting the top coilto the grid circuit of the top tube which is arranged at substantiallythe same level as the top coupling coil. The output or plate circuit ofthis top tube or first stage of the amplifier isthen connected to thethird coil or the coil next below the antenna coil which, in turn,supplies the input energy or-grid circuit of the second stage and so on,as will be described presently.

It is desirable to provide a cabinet for the re'- ceiving set of theinvention which will have small plan dimensions as well as a small or,convenient vertical dimension and to sufficiently utilize the mountingspace within this cabinet in order to permit the use of shortconnections between adjacent receiving apparatus. To accomplish this itis necessary to utilize the vertical depth or dimension of the cabinetin arranging the receiving apparatus therein. Accordingly, the chassisor apparatus mounting frame is provided of such shape as to permit thecompact arrangement of receiving apparatus at various vertical levels.It has been found that a substantially L-shaped chassis having asubstantially horizontal arm or member vand a relatively long verticalarm or member provides suflicient mounting space. to permit the use of acabinet for the receiving set which will be of convenient height for themanipulation of controls carried at the top of the cabinet by astanding, sitting or reclining operator. A chassis of such shape permitsmounting the receiving apparatus at opposite sides of both thehorizontal and vertical members and the use of such members as shieldsbetween the apparatus at opposite sides thereof.

f The invention further contemplates the provision of` such a novelchassis or frame for radio receiving sets which will be suspended from'acontrol panel or top for closing an open-top cabinet in which thechassis may be detachably secured and from which it may be readilyremoved. The chassis or frame is so constructed vand the receivingapparatus so arranged thereon that the chassis will be receivable in arelatively small vertical or upright cabinet or casing and when soassembled the control panel will be of convenient height, as alreadymentioned, for a standing, sitting or reclining operator or user of theset or system. This cabinet may be portable and, as here contemplated,may carry therein only the radio frequency amplifier, a portion of theaudio frequency amplifier and the radio control and operati ing devicesfor the receiving set. This unit so assembled is connectible by .acablewith asuitable source of energy or a power unit and separate audiofrequency apparatus. "Where desired this latter apparatus may alsoinclude a phonograph controlled from the control panel forming the topof the portable cabinet.

Illustrative of the invention, I provide a radio cabinet or casing 11having side and bottom panels 12 and 13 supported by'corner standards orframe members 14 terminating at their lower ends in feet or supports 15,as shown in Figures 1 and 2. The cabinet or casing 11 is adapted tohouse or encase a radio receiving set or system and for this purpose twoof the side panels 12 'may be provided with sound openings, asillustrated by the dotted lines 16 in Figure 1, to permit the escape ofsound from the loud speaker of the set. A substantially L-shaped chassisor frame 17, receivable in the cabinet, is adapted to carry thereceiving set. As illustrated, however, this chassis 17 carries a radiofrequency amplifier and detector together with the associated tuning andreceivingapparatus. A top 18 closes the top of the casing 11 when thechassis 17 is inserted therein, where the chassis is secured by means ofa retaining lug or bolt 19 projecting l from the chassis through anaperture 21 in the bottom panel 13, and a nut 22 threading on the bolt19. L f

The cabinet 11 is of such height asto render the control panel or top 18readily accessible by a standing, sitting or reclining operator for themanipulation of a control or on and oil switch 23, a tuning handle orknob 24, and a volume control handle or knob 25 on the control panel orcabinet top 18 and for viewing a glass or celluloid plate 26,substantially flush with the top 18v and closing a dial or sight opening27 therein. The control panel or top 18 is provided with suitablehandles 28 to render the cabinet portable. The handles 28 are adapted topivotally span aplate 29 having boltand nut assemblies 31 se-v curing itto the top 18. If desired, the plate 29 may be dished, as illustrated inFigures 1 and 2, and used as a receptacle for an varticle of personalconvenience .such as an ash tray.

As already mentioned, the chassis or Afram 17, shown more particularlyin Figures 2 and 3, is substantially L-shaped and is so fabricated thatrelatively light-gauge metal may be employed in its construction, landyet the chassis will have suiicient strength and rigidity to Vprovide amechanically stable and light mounting for vthe receiving apparatus.This L-shaped chassis or frame 17 has a relatively long vertical arm 32f:

formed as a channel with a face 33 and sides 34 and is riveted orspot-welded to a top plate 35. This top plate 35 is secured to the underside of the cabinet top or panel 18 by the bolt and nut assemblies 31 sothat the chassis 17 is suspended l from the top 18 and is slidablyreceivable in the cabinet. The top yplate 35 is cut away as at 36 toaccommodate a tuning dial pan 37 carrying an indicator dial 40 havingtransparent tuning indicia thereon. The relatively long `vertical arm 32is secured at its lower end to a relatively short horizontal arm or base38 by'corner tie plates 39 riveted vas at 41 to the channel or arm 32and as at 42 to the short horizontal arm 38.

The short horizontal arm 38 may be formed from a single sheet of metalto provide a skirt portion or depending sides 43, and legs 44 forsupporting the chassis 17 when it is removed fromv the cabinet or casing11. The legs 44 are adapted to proj ect through openings 45 in thebottom panel 13 and to be concealed behind the cabinet feet or supports15, the legs co-operating with the retaining bolt 19 to center thechassis in the casing. Fig. 8 shows'a schematic diagram of a radioreceiving set which may be encased in the cabinet 11. As shown, however,the receiving systemor set is divided and that part of the set shownabove the cable, schematically `illustrated at 46, is shown with'thevarious unitsin substantially the relative positions in which they aremounted in the cabinet 11, that part below the cable 46 being adapted tobe mounted outside the cabinet 11. Thus the embodiment of the inventionillustrated in Fig. 8 provides a multi-stage, 45

whereby to provide a portable remote control unit m for the radioreceiving set 'or system.

A portion of the audio frequency amplifier, together with the radiofrequency ampliner, is mounted on the chassis 17 in the cabinet 11 toavoid a high impedance connection between the detector output and theaudio frequency amplier.

The multi-stage, radio frequency amplifier, as shown in Fig. 8, is alsocarried by the chassisg17 and the various elements of the amplifier areso mounted andarranged on the chassis that the capacity effects betweenadjacent units are reduced to a minimum.

Successive stages of the amplifier are coupled by any suitable couplingmeans, such as by coils 47, 48, 49 and 51, respectively arranged in cupshields'52, 53, 54 and 55 projecting horizontally, one above the other,yfrom the rear face of the vertical channel 32 and by coils 56 in cupshield 57 secured to the lowermost face of the horizon'- tal arm 38inwardly of the depending sides 43 by a nut 58 threading on a lug orbolt 59.

The coil 48, as illustrated, has two windings 60 and 61 inductivelycoupled and receiving energy from a conductor 62 connected with anantenna 63. The conductor 62 is included in the cable 46 and suitablyshielded from the other conductors to provide a low capacity antennalead, A resistor 64 and switch 65 shunting the winding 60 in thegrounded antenna circuit provide for distant and local reception. Thewinding 6l has its terminals connected to the terminals of a tuning orvariable condenser 66 which with tuning or variable condensers 67, 68and 69 are secured one above the other in a condenser frame or housing70 by means of brackets 7l and bolt and nut assemblies 72.

The condenser housing or frame 70 is mounted on the rear face of thechannel '32 by means of bolt and nut assemblies 72', and the condenserstherein are provided with the usual movable plates fixed on a commonshaft 73 for operating or tuning the condensers. This shaft 73 carriesthe dial pan 37 havingr a sight aperture 37 therein for exposing aportion of the dial 40 which is secured in the pan by a ring 74, the pan37 being operable by coil springs 75 having corresponding ends attachedto the pan and other ends connected with a cord 76 operably engaging thetuning handle or knob 24 for tuning the set.

A light 77 secured to the channel 32 by a bracket 78 illuminates thedial or indicator 40 and the light is projected through the sightopening 27 on the plate 26 flush with or above the top 18 for indicatingthe tuned position of the condensers 66 to 69. In other words, an imageof the indicia on the indicator dial 40 is projected on the plate 26which is so positioned as to be visible from directly above the plate orfrom above and at an angle to the plate.

The coil 48 is arranged below the top coil 47 in the input circuit ofthe first radio frequency amplier stage, the top coil 47 being shuntedby the tuning condenser 67 and a condenser 79 and being connected bymeans of a conductor 80 to the grid of a 224 amplifier tube 81 supportedon a bracket 82 mounted on the inner face of the channel 32 between thechannel sides 34. This conductor 80 connects to the grid of the tube 8lthrough the top of the tube as shown in Figs. 3 and 8, and this feature,together with the vertical arrangement of the tube and the relativepositioning of the coils 47 and 48, permits the use of a grid lead orconductor of minimum length to prevent feedback effects due to thecapacitance between the grid lead 80 and leads in the output circuitofthe tube. iItwiill be .observed that the face 33.0f the channel 32,.ashere Vdescribed,serves as a shieldfbetween the. tube 81` and'v thedevices on theopposite sideof the channelface.

The output circuitzof the top. tube 81 `is inductively coupled bythecoil 49, the4 third coil from the top, to which the plate of the tube isconnected by. a conductor`83, to .theinput circuit of another'224amplier tube.-'84 mounted .onza bracket 35 attached tothe channel=32below the tube :81 and shielded therefromxby a: horizontal partition 86secured to the face33 of the .channelbetween thesidest34. A conductor187leading vinto the top of the tube'84 connectsy thecoil'49 to the grid ofthetube, as in the preceding stage. The .output circuit of theV tube841s .inductively coupled Vbythe coil 5l to which the plate of thetubeis connected by a conductor 88, to the inputcircuit ofathird 224amplifier tube 89 including a conductor 91 connecting the coil lwith thegrid of the tubeas in the previously describedstages.

The tube '89 is mounted in the angle made; by the vertical andhorizontal arms'32*I and. 38, respectivelypof the L-shapedframe yand onthe same side of the face'33 yasfthexcondensers 66to 69, the tube beingsupported on the horizontal arm or base 38. Thus a.cascade-connectedamplifier is providedl with the stagesarrangedin theorder of their numbers oneabovethe other. y'The output of the tube 89 isinductively coupled v,by the coil 56 mounted to the underside ofr thebase or horizontal arm 38 to the input of rar227 detector tube y92 bymeans of conductors 93I andz94. .This tube 92 is'mounted on the-.base 38adjacent the tube 89 Vand may be any suitable `detector such vas thatillustrated in which the cathode is'connected to the plate' in order toprovide a two element detector havingsubstantially linearcharacteristics.

The output of this radio frequencyamplifler and detector isccnnectedgthrough avariable resistance-or voltage divider 95, operablebythe volume control handle or knob 25-tofadjust the volume ofthereceived signal, to aV 227 amplifier tube-96'mounted on the-base38 inspaced relaticntothev tube 89 and shielded therefrom byfa substantiallysquare panel 97 upstanding from the base 38. The tube 96 is in the'firstaudiofrequency stagel and is mounted in the cabinet 11 in order toavoid a high impedance `connection between the detector output and theaudio frequency amplifier, such'asimayobtain when the. audio frequencyamplifier is remotely positioned with respect to the detector.

The cable 46 includes conductors98fconnecting the on and off or controlswitch 23,.-a conductor 99 for supplying energy to a transformer 101mounted on the base 38 between the `channel sides 34'forsupplyingcurrent to the filaments of the tubes 8l, 84, 89 and 96, a ground:conductor 102, the low capacity antenna conductor 62, and conductors'lo,104 and 165y for supplying energy to the radiofrequency amplifier andfor Vconnecting theoutput of the rst audio frequency stage with theinput of the next stage. This cable makes the foregoing connections'bymeans of :aj@ plug connector 106 depending from the base v38 inwardly ofthe sides 43 andy adapted to project through an aperture 110 in thebottom 13 of the cabinet 11, the plug 106 being complementary to aconnector member (not shown) on the cable.

The tubes'l, 84 4and 89,` as-illustrated, may bev of the four-element orscreen-grid type toprovide high amplifying characteristics. The screengrids of these tubes ,are so connected bymeans of a wire or conductor107 to a condenser 108'and to resistors 109 and 111as" toprovide asuitable biasl for these screengrids and to minimize the feed-.back ofhigh frequency current from the plates to the,` grids of the tubes.` Thecondenser 1081s mounted on ther face 33` just above the transformerllbymeans of va bracket 112 and a bolt and nutassembly 113'.;V

The tubes 81 and 84 vertically yarranged fone above the other, thetransformer 101, the condenser 108, andthe other apparatus mountedbetween the channel'sides may be enclosed by a closure plate 114rvcooperating with the channel 32. ,This plate 114 is provided withopenings or apertures 114' registeringwith the tubes 81 and 84 to exposethem to -view for inspection and to facilitate replacing the tubes, theplate 114 being suitably secured'to the .channel as by bolt and nutvassemblies 115 (see Fig. 2). The various condensers, resistors, andother apparatus are attached to the chassis or frame in substantiallythe relative positions illustrated in Fig. 8, the filter, designatedgenerally-by the reference character 116, being attached-to or suspendedfrom the underside of the base or arm 38 inwardly of the' dependingsides as shown by the dotted lines inFig. 3. f i i Thus, it will `beseen that the substantially L- shapedV chassis or Iframe provides acompact and mechanically rigid mounting for the units of a radioreceiving set' and facilitates shielding the units and wires from otherunits and wires to reducethe capacity effects to a minimum. By arrangingthe coils so that coil 48, the second coil from the top, 'is in theantenna circuit and coil 47fthe` topmost'coil', is connected by theconductor to thegrid of the first stage and is led into the; tubethrough its top, and by so arranging the succeeding stages that similarconnections are made, the grid leads are reduced to a minimum length.The mounting of the tubes, condensers, and coils on the vertical channel32 permits the use of a comparatively light gauge of metal for thechassis, thereby contributing to the provision ofr a light and portablereceiver or remote control unit fora receiver'.v This substantiallyL-shaped chassis also provides a large mounting surface for thereceivingapparatus so thatit is Vpossible to arrangethe units of thereceiving set on. allv sides of thechassis in order that it may be soconstructed as to beof convenient height for the manipulation of thecontrols by a standing, sitting or reclining operator.

If only the radio frequency amplifier, detector, a portion of the audiofrequency amplifier, and the tuning and control means of the radioreceiver are carried by the cabinet 11, the cable 46, schematicallyillustratedin Fig. 8, may extend to a suitable source of energy and tothe other audio frequency amplifier stages enclosed 'in the same cabinetor in different cabinets not shown.

As illustrated, atransformer 117, connectible by a plug 118 to asuitable electrical outlet which supplies current tc lthe transformers101 and 117 through the conductors `98 and 99, is controlled by thecontrol switch 23 in the cabinet 11. This transformer 117 is providedwith secondary windings 119, 121, 122 and'123 for supplying electricalenergy to the set. The winding 119 supplies current to the filamentsofrtwo 245 audio frequency tubes v120 and 124, the grids of which areconnected together through the secondary of a transformer 125, theprimary of which couples them to the' output circuit of`a'227 'audiofrequency amplifier tube '126 having a resistance coupling with the rst4audio* frequency-stage by means of -conductors 104 and 105'in cable 46.The filament of tube 126 issupplied with energy from coil' 121 of thetransformer 117.

The plates of the tubes 120 and 124 are connected together through theprimary winding of a transformer 127, the secondaryof which suppliesenergy to a'loudzspeaker 128. The winding 122 suppliescurrent 'to thefilament of a 280 rectifier tube 129 which rectiiies the output of coil123 and supplies this rectified currentto a filter generally designatedat 131. Conductors 132 and 133 connect intermediate points of thisiilter with intermediate points of the secondary and primary windings oftransformers 125 and 127, respectively. The output of the filter 181 isconnected by the wire 104 tothe plate circuits of the tubes in thecabinet 11. It will be understood that any suitable energy supply unitand audio frequency amplifier -may be employed with the radio frequencyamplifier and control unit in the cabinet 11 and that the invention isnot limited tothe detailed description above.

Whe-re desired, a selective switch 134 (see Fig. 8) for selectivelycontrolling the radio set and a phonograph, not shown, may be employedto disconnect the radio frequency amplifier, leaving the audio frequencyamplifier connected for use with the phonograph. The switch 134 may bemounted on the control panel or top 18 or a single, multi-point switchmay replace the switches 23 and 134. For this purpose a condenser 135may be connected in the antenna circuit between the antenna 63 and thecoil 48 and between a contact point 136 of the switch 134, providing aphonograph connection, and the coil 48 to avoid short circuiting theaudio frequency amplifier through the coil 48 while the phonograph isbeingfoperated. A phonograph pick-up, diagrammatically illustrated by acoil 137 in series with a radio frequency choke coil or inductance 138,may also bev connected' to the contact point 136 of the switch 134 forstopping the phonograph when the switch 134 is thrown from the point 136to a radio frequency amplifier for radio reception. The choke coil 138prevents short circuiting of the antenna 63 while the radio is beingused. l The energy supply for the phonograph pick-up may be carried bythe antenna conductor 62 whereby to substantially prevent capacitycouplingv betweenthis conductor and the other conductors in the cable46. Attention is here again directed to the mounting of the audiofrequency tube 96 in the cabinet 11.v Such a mounting, in addition tothe advantage of avoiding high impedance in the output of the detectorstage, permits the volume of the phonograph to be controlled from thecabinet 11. 4

Thus the cabinet 11 may be so constructedI that the control panel willbe at a convenient height for the manipulation of the control and tuningdevices by a standing, sitting or reclining operator. The cabinet beingadapted to slidably receive through its open top a substantially L-shaped chassis or frame, carrying receiving apparatus at opposite sidesof both the vertical and horizontal arms. These arms or members servingas shields permit the vertical arrangement of coupling coils and tuningcondensers at one side of the vertical arm and amplifier tubesvertically arranged one above the other at the opposite side of theVertical arm of the chassis or frame so that energy is supplied from theoutput of one tube to the input of a tube next below the first tube.Such an arrangement of receiving apparatus permits arranging the coilsin such positions that the grid leads or conductor from each coil to thecorresponding tube has a minimum length whereby to minimize feed-backeffects caused by long grid leads being capacitively coupled with otherapparatus and wires.

Furthermore, the vertical arrangement' of the tubes, condensers andcoils permits the use of arelatively light vertical arm as a mountingfor this apparatus and the chassis or frame carrying the receivingapparatus may be suspended from a control panel adapted to serve as aclosure for the cabinet whereby to provide a compact and sightlyassembly. By providing the top separable from the cabinet, the receivingapparatus may be Withdrawn from the cabinet simply by removing the top,thereby facilitating inspection, repair and replacement of parts.

While I have illustrated a preferred embodiment of my invention, manymodications may be made without departing from the spirit of theinvention, and I do not wish to be limited to the precise details ofconstruction set forth, but desire to avail myself of all changes withinthe scope of the appended claims.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent of the United States is:

1. A radio receiving set including thermionic tubes in combination witha chassis having a vertical channel member and carrying receivingapparatus, a plurality of said thermionic tubes being verticallyarranged in superposed and shielded relation within said verticalchannel member, and other thermionic tubes arranged behind said verticalchannel member.

2. A radio receiving set comprising a substantially L-shaped chassis forreceiving and tuning apparatus, having a metallic base and a verticalmetallic channel member mounted on said base, a plurality of thermionictubes carried by said base outside of said channel member, and aplurality of thermionic tubes arranged vertically one above the otherand carried within said channel member, the first said thermionic tubebeing shielded from the last said thermionic tubes by the central web ofthe channel member.

3. A radio receiving set comprising a substantially L-shaped chassis forreceiving and tuning apparatus, having a metallic base and a verticalmetallic channel member mounted thereon, said base having dependingsides, receiving and tuning apparatus mounted on said vertical channelmember at opposite sides thereof, receiving apparatus mounted on saidbase at opposite sides of said vertical channel member, and otherreceiving apparatus mounted under said base inwardly of said dependingsides.

4. A radio receiving set having an energy supply source and audioapparatus in combination with an L-shaped metallic chassis having avertical channel member and a relatively short horizontal membersupporting said vertical arm, a multi-stage amplier mounted on saidchassis, said horizontal arm having depending sides and providing amounting at opposite sides thereof for ampliiier apparatus, saidamplifier apparatus being mounted on, and within and without saidchassis members.

5. A radio set comprising a rigid chassis having a vertical metallicchannel member and a relatively short horizontal channel member securedthereto, said members being adapted to carry radio receiving apparatus,radio frequency and audio frequency thermionic tubes supported on saidhorizontal member at a side of said vertical member, a shield betweensaid audio frequency and radio frequency tubes, and other radiofrequency thermionic tubes supported within said vertical channel memberand shielded thereby from the nrst said tubes.

6. A radio receiving set comprising a cabinet, an energy supply source,a vertical chassis comprising a vertical metallic sheet positionable insaid cabinet, a multi-stage amplifier carried by said chassis andconnectible with said energy supply source, said amplier including stagecouplers mounted one above the other on one side of said vertical sheet,and a plurality of vertical screen grid tubes arranged one above theother on the opposite side of said sheet, one of said stage couplersbeing located at a height adjacent the base of one tube and the top ofthe other tube to which it is connected so that the connections betweenthe couplers and tubes may be short.

7. A radio receiving set in combination with a cabinet having bottom andside walls providing a vertical enclosure for said radio receiving set,said bottom wall having a plurality of apertures therein, a controlpanel for said receiving set forming a top closing said verticalenclosure, an L-shaped chassis suspended from said top and slidablytting within said enclosure, said chassis carrying a portion of saidreceiving set, means projecting from said chassis and co-operating withsaid apertures to position and to detachably secure said chassis withinsaid enclosure, and a handle on said control panel for removing saidchassis from said casing.

8. A radio receiving set in combination with a casing having a separabletop, an L-shaped chassis comprising two channel members secured togetherat right angles carrying said receiving apparatus and positioned in saidcasing, and a plate positioned on said top and secured to said chassisto suspend said chassis from said top.

9. A radio receiving set comprising a cabinet having an open top, asubstantially L-shaped chassis comprising two channel members securedtogether at right angles receivable in said cabinet through said opentop, receiving apparatus mounted on both sides of the channel members ofsaid chassis and a cover secured to said chassis and control meansthereon.

10. A radio set comprising an open top cabinet, receiving and tuningapparatus therein, and a substantially L-shaped chassis comprising twochannel members secured together at right angles supporting saidreceiving and tuning apparatus in said cabinet, said chassis beingremovable through the top of said cabinet, and a cover secured to saidchassis.

11. A radio receiving set in combination with a chassis for the radioreceiving set, comprising an L-shaped framev having a base provided withdependingvsides, and a top, said top and base being connected by saidvertical channel.

EDWARD F. ANDREWS.

